In many engineering applications, it is necessary to monitor a supply or flow of a pressurized gas, such as oxygen. This is particularly applicable in the fields of medicine and aviation. Current devices that monitor an oxygen system's status for medical and aircraft applications are generally by one of two types. The first type of such monitoring system relies on the use of pneumatic gages that may be prone to inaccuracies, and are neither durable or reliable. The second type of such system uses electronic sensors or switches that may be more durable and accurate that the pneumatic gages, but are prohibitively expensive in many applications and therefore not cost effective.
A typical application (e.g., an aircraft gaseous oxygen system) is illustrated in FIG. 1. Although throughout this document the term “oxygen” is used to discuss the gas, it should be understood that air or any other pressurized gas could be used with the present invention. A similar discussion could apply to a medical oxygen systems or other types of oxygen systems. In the system depicted in FIG. 1, high pressure oxygen such as 2000 psi is stored in the oxygen cylinder assembly 18, secured by cylinder mounting brackets 21. The oxygen cylinder assembly 18 includes a high pressure hose 6 that leads to an overboard discharge outlet 25 in case of overpressurization. A first high pressure line 20 leads to a fill valve 5 and a second high pressure line 22 mates with a tee fitting 23, that leads to a pressure transducer 19 and a pressure gauge 2 for monitoring the pressure. A low pressure hose 17 feeds another system via a low pressure switch 3. A regulating device that is a component of the oxygen cylinder assembly maintains an operating output pressure of 70 psi. In order to determine the amount of oxygen remaining in the system, the pressure in the cylinder is monitored by both a pressure gauge 2 and pressure transducer 19. Additionally, a low pressure switch or another pressure transducer 3 monitors the regulated output and remains closed as long as a minimum regulated pressure is present. These devices are in continuous operation and the pressure transducer 19 and low pressure switch 3 are continuously drawing power whenever the aircraft is operating. Thus, it would be beneficial to provide a system and method which is more accurate and draws less power than previous systems.